An elongated workpiece may need to be processed uniformly along its length. This can be accomplished by driving the workpiece through a rolling machine. For example, a pipe or other tubular structure may need to be straightened, and certain rolling machines are configured to function as straightening machines. One such machine is shown is shown in FIGS. 1 and 2.
In the illustrated example, the straightening machine 10 has a base 12 and a crown 14. The base 12 stands on a shop floor 16. The crown 14 is supported on pillars 18 at a fixed height above the base 12. Both the base 12 and the crown 14 have a rectangular shape with opposite ends 20 and 22, a drive side 24, and an operator side 26.
The machine 10 further has hyperbolically shaped straightening rolls 34 and 36 between the base 12 and the crown 14. The rolls 34 and 36 are arranged in pairs that are spaced apart in a horizontal line of roll pair locations 39 reaching along the length of the machine 10. The given example is a six roll machine with three pairs of rolls, each of which includes an upper roll 34 and a lower roll 36. The upper and lower roll 34 and 36 in each pair are opposed across a vertical gap between them.
The rolls 34 and 36 are supported on the crown 14 and the base 12 for relative movement into and out of operative positions. When in the operative positions, the rolls 34 and 36 in each pair are skewed horizontally relative to one another, and the vertical gap has a reduced size defining a nip for receiving a workpiece between the rolls 34 and 36.
As shown in FIG. 2, each roll 34 and 36 is coupled to a respective drive shaft 40 at the drive side 24 of the machine 10. The drive shafts 40 project from the rolls 34 and 36 to respective motors in a drive assembly (not shown) that is mounted on the floor 16 separately from the machine 10. In operation, the rolls 34 and 36 are rotated by the drive shafts 40 to move a tube or other elongated workpiece through the nips along the line of roll pair locations 39. This straightens the workpiece as the skewed concave surfaces of the rolls 34 and 36 force the workpiece onto a working axis at each nip.